Because the preferred embodiments disclosed below are primarily directed to applications within the field of pharmaceutical manufacture, the background and needs addressed in that field are discussed below in relatively greater detail, with a few brief comments directed to the other fields of use. The delivery of pharmaceutical chemicals, or medications, or “medicaments” for therapeutic purposes is currently accomplished by ingesting a “pill” to be taken into the digestive tract, by breathing aerosolized liquids or powders for intake into the respiratory tract, and by direct injection or by transdermal diffusion into the circulatory system of mammals. In many current applications of these delivery methods, the bioactive component is a small, of the order of about lot, of the total delivery of active and inert material. The larger portion is a more or less inert material such as starch powders in the case of pill delivery, water or alcohol, or a mixture thereof, for inhalation delivery, or saline solution for injection or transdermal delivery. As a common example, in a pill which is formed by mixing active and inert powders, the active dose may have mass of 10 milligrams and the inert carrier may have mass of 100 milligrams, with the resulting active/inert mass ratio of the order of 10:100 or 10%.
It will be appreciated that known formulation or mixing technologies make it difficult to achieve good precision and accuracy even when the dose is about 10 mg and the active/inert fraction is about 10%. Prior art technologies limit the precision in the delivery, pill-by-pill, of the active medicament, to about 15%. Batch-to-batch absolute accuracies of about 10% are typical of current art. (As employed herein, precision means standard deviation divided by the mean of individual dosages within a batch. As employed herein, accuracy means the degree to which the average and absolute dosage of each batch agrees with the prescribed value.) Since these precisions and accuracies become even worse as the ratio of active to inert components falls, it follows that prior art mixing is severely limiting progress and dramatic improvements are needed. These limitations of prior art deliveries, to high active/inert fractions and high dosages, are thus in conflict with two of the much-desired features of modern pharmacology: decreasing active/inert fractions and decreasing active dose size. It can be appreciated that what matters, for proper therapeutic treatment, is the precision and absolute accuracy in the delivery of the active component, and of its bioavailability. The precision and accuracy in delivery of the inert carrier do not matter, as much. It can be further appreciated that the prior art precisions and accuracies are discomfortingly problematical, even for today's relatively high dosage levels and high active/inert fractions. Some pharmaceuticals are potentially harmful in even slight overdoses. On the other hand, underdosing will not produce the desired therapeutic results. Using the 15% precision and 10% accuracy values given above, the worst-case combinations of pill-to-pill precisions and batch-to-batch accuracies statistically allow, with disconcerting frequency, more than ±25% dosage variabilities with respect to the dosage prescribed by the physician, and expected by the patient. It follows that the variabilities in dosage deliveries associated with prior art apparatus and methods are only marginally acceptable now, with high dose levels and high active/inert fractions, and are increasingly unacceptable as the level or fraction decrease, and are thereby limiting progress.